Outage in Loop Returns
Label gen failing for Ship by Loop merchants using USPS Ship
Resolved Minor
April 17, 2026 - Started 10 days ago
- Lasted about 3 hours
Incident Report
Summary AI Generated
Loop Returns experienced increased label generation failures for Ship by Loop merchants using USPS Ship rates due to sender email addresses exceeding the 50-character limit in EasyPost's validation system. The issue affected the Returns Portal for 2.7 hours, preventing merchants from successfully purchasing shipping labels. The problem was resolved by running a script to update the problematic email addresses associated with EasyPost accounts for USPS Ship merchants.
We are seeing an increase in label failures for SBL merchants using Loop's negotiated USPS rates post migration to USPS Ship. We have identified a fix and working on both a short term resolution and long term fix with EasyPost. The error message in the timeline will be a bit cryptic and look something like this. Additional update in 5 minutes.
"An error occurred: Purchasing the shipping label failed — EasyPost: /labels/v3/: code=400, message=OASValidation OpenAPI-Spec-Validation-Labels with resource oas://labels-v3.yaml: failed with reason: [ERROR - [Path '/senderAddress'] Instance failed to match all required schemas (matched only 2 out of 3): __/properties/senderAddress/allOf/0: Instance failed to match all required schemas (matched only 2 out of 3)__ERROR - [Path '/senderAddress'] Instance failed to match all required schemas (matched only 2 out of 3): [/properties/senderAddress/allOf/0/allOf/2: String __referral_customer_6ffe2bef032046e1926c76dde09b3119@donotemail.easypost.com__ is too long (length: 74, maximum allowed: 50)]ERROR - [Path '/senderAddress/email'] String __referral_customer_6ffe2bef032046e1926c76dde09b3119@donotemail.easypost.com__ is too long (length: 74, maximum allowed: 50): []]"
"An error occurred: Purchasing the shipping label failed — EasyPost: /labels/v3/: code=400, message=OASValidation OpenAPI-Spec-Validation-Labels with resource oas://labels-v3.yaml: failed with reason: [ERROR - [Path '/senderAddress'] Instance failed to match all required schemas (matched only 2 out of 3): __/properties/senderAddress/allOf/0: Instance failed to match all required schemas (matched only 2 out of 3)__ERROR - [Path '/senderAddress'] Instance failed to match all required schemas (matched only 2 out of 3): [/properties/senderAddress/allOf/0/allOf/2: String __referral_customer_6ffe2bef032046e1926c76dde09b3119@donotemail.easypost.com__ is too long (length: 74, maximum allowed: 50)]ERROR - [Path '/senderAddress/email'] String __referral_customer_6ffe2bef032046e1926c76dde09b3119@donotemail.easypost.com__ is too long (length: 74, maximum allowed: 50): []]"
Components affected
Loop Returns Returns PortalTrusted by 1,000+ teams
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Latest Updates ( sorted recent to last )
10 days ago - at 04/17/2026 10:09PM
We are seeing an increase in label failures for SBL merchants using Loop's negotiated USPS rates post migration to USPS Ship. We have identified a fix and working on both a short term resolution and long term fix with EasyPost. The error message in the timeline will be a bit cryptic and look something like this. Additional update in 5 minutes.
"An error occurred: Purchasing the shipping label failed — EasyPost: /labels/v3/: code=400, message=OASValidation OpenAPI-Spec-Validation-Labels with resource oas://labels-v3.yaml: failed with reason: [ERROR - [Path '/senderAddress'] Instance failed to match all required schemas (matched only 2 out of 3): __/properties/senderAddress/allOf/0: Instance failed to match all required schemas (matched only 2 out of 3)__ERROR - [Path '/senderAddress'] Instance failed to match all required schemas (matched only 2 out of 3): [/properties/senderAddress/allOf/0/allOf/2: String __referral_customer_6ffe2bef032046e1926c76dde09b3119@donotemail.easypost.com__ is too long (length: 74, maximum allowed: 50)]ERROR - [Path '/senderAddress/email'] String __referral_customer_6ffe2bef032046e1926c76dde09b3119@donotemail.easypost.com__ is too long (length: 74, maximum allowed: 50): []]"
10 days ago - at 04/18/2026 12:44AM
We ran a script to update problematic email addresses associated to the easypost account for usps ship merchants. Now monitoring and verifying the changes
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